# Copyright 2021-2024 VyOS maintainers and contributors <maintainers@vyos.io>
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with this library.  If not, see <http://www.gnu.org/licenses/>.

# T1968: allow multiple static-routes to be configured
# T3838: rename dns-server -> name-server

from vyos.configtree import ConfigTree

base = ['service', 'dhcp-server']

def migrate(config: ConfigTree) -> None:
    if not config.exists(base + ['shared-network-name']):
        # Nothing to do
        return

    # Run this for every instance if 'shared-network-name'
    for network in config.list_nodes(base + ['shared-network-name']):
        base_network = base + ['shared-network-name', network]

        if not config.exists(base_network + ['subnet']):
            continue

        # Run this for every specified 'subnet'
        for subnet in config.list_nodes(base_network + ['subnet']):
            base_subnet = base_network + ['subnet', subnet]

            # T1968: allow multiple static-routes to be configured
            if config.exists(base_subnet + ['static-route']):
                prefix = config.return_value(base_subnet + ['static-route', 'destination-subnet'])
                router = config.return_value(base_subnet + ['static-route', 'router'])
                config.delete(base_subnet + ['static-route'])

                config.set(base_subnet + ['static-route', prefix, 'next-hop'], value=router)
                config.set_tag(base_subnet + ['static-route'])

            # T3838: rename dns-server -> name-server
            if config.exists(base_subnet + ['dns-server']):
                config.rename(base_subnet + ['dns-server'], 'name-server')


            # T3672: ISC DHCP server only supports one failover peer
            if config.exists(base_subnet + ['failover']):
                # There can only be one failover configuration, if none is present
                # we add the first one
                if not config.exists(base + ['failover']):
                    local = config.return_value(base_subnet + ['failover', 'local-address'])
                    remote = config.return_value(base_subnet + ['failover', 'peer-address'])
                    status = config.return_value(base_subnet + ['failover', 'status'])
                    name = config.return_value(base_subnet + ['failover', 'name'])

                    config.set(base + ['failover', 'remote'], value=remote)
                    config.set(base + ['failover', 'source-address'], value=local)
                    config.set(base + ['failover', 'status'], value=status)
                    config.set(base + ['failover', 'name'], value=name)

                config.delete(base_subnet + ['failover'])
                config.set(base_subnet + ['enable-failover'])